Some inkjet printers have an inkjet head in which ink circulates in a channel in the head. Inkjet heads of this type includes a supply port to which ink is supplied, and a discharge port from which ink is discharged. The inkjet heads have a plurality of piezoelectric elements which are arranged between the supply port and the discharge port.
Ink supplied from the supply port is ejected from nozzles of the inkjet head by piezoelectric elements. The nozzles are opposed to the piezoelectric elements. The remaining ink is recovered into an ink tank through the discharge port.
The piezoelectric elements are formed of, for example, lead zirconate titanate (PZT). Each piezoelectric element includes a plurality of groove parts, which are formed by machining, and a plurality of supports. By applying voltage to the supports, the pressure in the groove parts changes. Thereby, ink in the groove parts is ejected from the nozzles.
The piezoelectric elements are formed in a bar shape, and arranged in parallel with each other. Pressure chambers of the piezoelectric elements are formed of, for example, a dicing saw. A diamond wheel of a dicing saw moves to cross a plurality of piezoelectric elements. Thereby, groove parts are formed in the piezoelectric elements at a time.
The diamond wheel deteriorates due to, for example, wearing, during processing. When machining is performed with a worn diamond wheel, the groove parts are narrowed, and the supports are formed with an increased thickness. When the thickness of the supports increases, the deformation quantity of the supports when the voltage is applied decreases, and the quantity of ejected ink is also reduced. As described above, deterioration of the machining tool during processing may cause, for example, unevenness in density in printing.